■ adjective
1》 (usu. in phr. ~ and void ) having no legal force; invalid.
2》 having or associated with the value zero.
↘ Mathematics (of a set or matrix) having no elements, or only zeros as elements.
3》 having no positive substance.
■ noun
1》 a dummy letter in a cipher.
2》 Electronics a condition in which no signal is generated; something generating no signal.
■ verb Electronics cancel out, creating a ~.
Origin
ME: from Fr. nul , ~e , from L. ~us 'none', from ne 'not' + ullus 'any'.